Clot retrieval device for removing occlusive clot from a blood vessel

Abstract

A clot retrieval device for removing occlusive clot from a blood vessel. The device comprises an inner elongate body having a collapsed delivery configuration and an expanded deployed configuration. An outer elongate body is at least partially overlying the inner elongate body. The outer elongate body is expandable to a radial extent which is greater than the radial extent of the inner body in the deployed configuration to define a clot reception space. The outer elongate body has a plurality of clot receiving openings and a plurality of clot engaging regions. The clot engaging regions are adapted, on engagement with clot, to urge clot towards the clot receiving openings and into the reception space between the outer elongate body and the inner elongate body, wherein the radial force profile of the device varies along the length of the device.

What is claimed is: 
     
       1. A clot retrieval device for removing occlusive clot from a blood vessel, the device comprising:
 an inner elongate body comprising a collapsed delivery configuration and an expanded deployed configuration; and 
 an outer elongate body at least partially overlying the inner elongate body, the outer elongate body being expandable to a radial extent which is greater than the radial extent of the inner elongate body in the deployed configuration to define a clot reception space; 
 wherein the outer elongate body comprises a plurality of clot inlet openings and a plurality of clot engaging regions, wherein the clot engaging regions are adapted, on engagement with the occlusive clot, to urge the occlusive clot towards the clot inlet openings and into the clot reception space between the outer elongate body and the inner elongate body; 
 wherein a diameter of the inner elongate body varies along the length of the inner elongate body and a diameter of the outer elongate body varies along the length of the outer elongate body; 
 wherein the radial force profile of the device varies along the length of the device; and 
 wherein a size of a first clot inlet opening of the plurality of clot inlet openings and a second clot inlet opening of the plurality of clot inlet openings is different than a size of the second clot inlet opening of the plurality of clot inlet openings and a third clot inlet opening of the plurality of clot inlet openings. 
 
     
     
       2. The device as claimed in  claim 1  wherein the radial force at a distal end of the device is lower than that at a middle section of the device. 
     
     
       3. The device as claimed in  claim 1  wherein and the radial force of one clot engaging region is different than the radial force of at least one other clot engaging region. 
     
     
       4. The device as claimed in  claim 1  wherein the difference in radial force between the clot engaging regions is less than 20%. 
     
     
       5. The device as claimed in  claim 1  wherein the outer elongate body comprises a diameter that tapers along the length of the device. 
     
     
       6. The device as claimed in  claim 5  wherein the outer elongate body tapers from a smaller proximal diameter to a larger distal diameter. 
     
     
       7. The device as claimed in  claim 5  wherein the outer elongate body tapers from a larger proximal diameter to a smaller distal diameter. 
     
     
       8. The device as claimed in  claim 1  wherein in the expanded deployed configuration the inner elongate body expands to a diameter that is significantly smaller than a diameter of the blood vessel immediately adjacent to and distal of the occlusion. 
     
     
       9. The device as claimed in  claim 1  wherein the inner elongate body comprises a diameter that varies between 0.75 mm and 2.5 mm. 
     
     
       10. The device as claimed in  claim 1  wherein the inner elongate body comprises a diameter that varies between 0.75 mm and 1.75 mm. 
     
     
       11. The device as claimed in  claim 1  wherein the inner elongate body comprises a generally conical shape. 
     
     
       12. The device as claimed in  claim 1  wherein the inner elongate body comprises a diameter that tapers along the length of the device. 
     
     
       13. The device as claimed in  claim 12 , wherein the inner elongate body tapers from a smaller proximal diameter to a larger distal diameter. 
     
     
       14. The device as claimed in  claim 12 , wherein the inner elongate body tapers from a larger proximal diameter to a smaller distal diameter. 
     
     
       15. The device as claimed in  claim 1  wherein the inner elongate body tapers from a diameter in a range of approximately 0.75 mm-1.75 mm to diameter in a range of approximately 1.5 mm-4.0 mm. 
     
     
       16. The device as claimed in  claim 1  wherein there is a gradient of the size of the clot inlet openings in the outer elongate body along the length of the device. 
     
     
       17. The device as claimed in  claim 16  wherein the gradient increases from proximal to distal. 
     
     
       18. The device as claimed in  claim 16  wherein the gradient decreases from proximal to distal. 
     
     
       19. The device as claimed in  claim 16  wherein the size of the inlet openings varies between approximately 1.0 mm{circumflex over ( )}2 and approximately 3.0 mm{circumflex over ( )}2. 
     
     
       20. A clot retrieval device for removing occlusive clot from a blood vessel, the device comprising:
 an inner elongate body comprising a collapsed delivery configuration and an expanded deployed configuration; and 
 an outer elongate body at least partially encircling the inner elongate body; 
 the outer elongate body being expandable to a radial extent which is greater than the radial extent of the inner elongate body in the deployed configuration to define a clot reception space; 
 the outer elongate body comprising a plurality of clot receiving openings and a plurality of clot engaging regions, wherein the clot engaging regions are adapted, on engagement with the occlusive clot, to urge the occlusive clot towards the clot receiving openings and into the clot reception space between the outer elongate body and the inner elongate body, 
 wherein the outer elongate body comprises a framework formed by struts and crowns and wherein proximal radiopaque markers are located at a distal end of struts which are proximally adjacent to proximal crowns; 
 wherein a diameter of the inner elongate body varies along the length of the inner elongate body and a diameter of the outer elongate body varies along the length of the outer elongate body; and 
 wherein a size of a first clot inlet opening of the plurality of clot inlet openings and a second clot inlet opening of the plurality of clot inlet openings is different than a size of the second clot inlet opening of the plurality of clot inlet openings and a third clot inlet opening of the plurality of clot inlet openings.